The invention relates to a carrier structure, particularly for optical components, comprising a carrier body with hollows (hollow spaces) and at least one cover layer which is arranged on at least one surface of the carrier body. The invention relates in particular to a lightweight carrier structure for an optical mirror or for a dynamically movable carrier platform, e.g. for optical components. The invention also relates to a method for producing a carrier structure of this type. Applications of the invention exist in particular in the case of the production of optical components or carriers for optical components.
A lightweight carrier structure is a mechanical component, the mass of which is minimized by means of the formation of hollows in a carrier body of the carrier structure. A hollow honeycomb structure, which is characterized by a high mechanical stability, can be formed for example in the carrier body. Applications of lightweight carrier structures exist for example in optics and precision engineering, if components should be as light as possible, e.g. for transport purposes or for a fast dynamic response behavior. In addition to the minimal mass, further requirements can exist in relation to the mechanical stability (in particular strength and rigidity), the thermal stability (in particular geometric stability in the case of temperature changes) and the resistance against external influences, such as e.g. chemicals or highly energetic radiation. Furthermore, there exists an interest in a high long-term stability, i.e. insomuch as it is possible, the mechanical and thermal properties should not change during the lifetime of the carrier structure.
It is known from practice to produce a lightweight carrier structure with a milled out carrier body, wherein the hollows in the carrier body are open on one side. It can be advantageous that a plurality of materials for carrier structures of this type are suitable and the carrier structure can be produced in a simple manner. Disadvantages exist, however, with reference to differences of mechanical or thermal properties which can occur on different sides of carrier bodies of this type due to the absence of symmetry. Therefore, carrier bodies with closed hollows, in which the hollows are enclosed on all sides by the material of the carrier body, are preferred for precision applications.
Carrier bodies with closed hollows place particular requirements on the production method. For example, closed hollow structures can be produced from beryllium, wherein considerable difficulties result from the toxicity of the material, however. Ceramic carrier bodies with hollows are also known from practice, which ceramic bodies are formed in a precursor state of the ceramic and are filled with a filler. The filler is removed after the sintering of the ceramic. This technology has disadvantages in relation to the complexity of conducting the method and limitations with reference to the geometry of the hollows that can be set.
Furthermore, it is known from practice to provide carrier bodies with hollow spaces with cover layers on one or both sides in order to close the hollows. The connection between the cover layer, which e.g. consists of glass, and the carrier body, e.g. made from ceramic, has hitherto been produced e.g. with a glass solder or an adhesive. Such connection types have proven insufficiently stable in the case of numerous applications.
Particularly high stability requirements exist on carrier structures for optical applications, such as e.g. for mirrors, which are used in optical communication between satellites or in optical telescopes. So, mirror bodies for satellite communication (CPA, “Course pointing assembly” systems) for transporting into space and operation on satellites must have a mass which is a small as possible, a high rigidity and dimensional precision because of the high accelerations and a high thermal stability because of the extreme temperature differences on the light and dark side of up to 200° C. Mirror bodies for CPA systems have hitherto been produced e.g. from beryllium, which has the above-mentioned disadvantages, however.
It is the objective of the invention to provide an improved carrier structure, particularly for optical components, with which carrier structure the disadvantages of conventional lightweight carrier structures are overcome. The carrier structure should in particular be characterized by a high mechanical stability, thermal stability and/or long-term stability and be producible in a simple manner. The carrier structure should furthermore be characterized by an improved rigidity and dimensional precision, stability with respect to temperature fluctuations, variability in the case of the selection of a hollow geometry and/or resistance to chemical influences or radiation influences. Furthermore, it is the objective of the invention to provide an improved method for producing a carrier structure, with which disadvantages of conventional methods for providing lightweight carrier structures are overcome.
These objectives are achieved by means of a carrier structure or a method for its production according to the invention.